Thermostatic expansion valve



April 17, CARTER 1 THERMOSTATIC EXPANSION VALVE Filed Feb. 18, 1946 IN V EN TOR.

M ATTORNEY Patented Apr. 17, 1951 THERMOSTATIC EXPANSION VALVE Franklyn Y. Carter, Dearborn, Mich., assignor to Detroit Lubricator Company, Detroit, Mich., a

corporation of Michigan Application February 18, 1946, Serial No. 648,223 6 Claims. (Cl. 236-92) This invention relates to new and useful improvements in thermostatic expansion valves for controlling the flow of refrigerant.

An object of this invention is to provide a valve which can be readily taken apart for cleaning and replacement of parts.

Another object is to provide such a valve which may be hermetically sealed in and to the liquid lines by brazed joints without damage to the temperature responsive power element.

Another object is to provide a valve in which valve structures of different flow sizes or capacities are interchangeably useable in the same valve body or shell.

Another object is to provide a valve in which the valve body or shell is adapted to receive thermostatic power elements of different sizes.

The invention consists in the construction and combination of parts which will be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, to be taken as a part of this specification, there is fully and clearly illustrated a preferred embodiment of the invention, and in the drawings,

Figure 1 is a view in longitudinal central section of a thermostatic expansion valve, taken on the line of Fig. 3 and showing portions of the refrigerant conduits connected thereto,

Fig. 2 is a view in front elevation of the valve,

Fig. 3 is a bottomplan view of the valve,

Fig. 4 is a detail view in section on theline 4-4 of Fig. 2, and b Fig. 5 is an exploded view in elevation of certain of the parts of the valve.

'Referring to the drawings by characters reference, I designates the tubular metal shell or body of the thermostatic expansion valve which is shown as of the multiple outlet type having outlet connections 2, 3 in horizontal alinement at one end of the body. Fitted and'hermetically sealed, as by brazing, in the connections 2, 3 respectively, there are liquid line outlet conduits 4, for connection to the inlets of separate evaporators. Intermediate the ends of the shell or body I, there is an inlet connection 6 having a liquid inlet conduit 1 leading from the refrigerant condensing unit (not shown) The conduit 1 is fitted and sealed hermetically, as by brazing, in the connection 6. Within the shell I, there is an annular shoulder 8 dividing the shell internally into an inlet compartment 9 and an outlet compartment 10. Opening into the compartment 9 from the inlet connection '6, there spectively tothe interior of the connections 2, 3.

The shell I receives a tubular body member M'WhlCh is circumferentially stepped intermediate its ends to provide annular shoulders l5, It, the shoulder I5 seating against the shoulder 8 and separating the compartments 9 and ID. A gasket I! is positioned between the shoulders to seal the joint. The shoulder l6 reduces the cross section of the body member l4 and forms an end wall of the compartment ID. The portion of the body member between the shoulders l5 and i6 fits the outlet compartment side wall to centrally locate and laterally support the body memher in the shell; The compartment 0 has a centrally apertured end wall l8 which also forms the end wall of the shell I which is open at its other end to receive the body member l4. Seating against the end wall 8, there is an annular shoulder IS on the body member I4. Between the shoulder l9 and the wall l8, there is a sealing gasket 20. Within the member l4, there is a valve seat 2| providing a valve port and dividing the interior of member l4 into an inlet chamber 22 and an outlet chamber 23. Cooperable with the seat 2|, there is a conical valve member 24 having a stem 25 which extends through the chamber 23 and a guideway in the chamber end wall. Leakage through the guideway around the stem 25 is prevented by packing means 26, preferably a packing material plug and nut. The outlet chamber 23 communicates with the outlet compartment Ill through inclined passageways 21, 28 having their discharge ends directed respectively toward the outlet passageways l2 and I3. The'valve member 24 is rigidly secured to the end wallof a thirnble-like spring guide member 30 by a stud 29 projecting from the member 24 and screw-threaded into the end wall. The member 30 has a surrounding flange 3| on which one end of a'helical coil spring 32 seats, the spring surrounding the member 30 and being held under compression against the inlet chamber end wall around the valve seat 2| so as to urge the valve member 24 toward open position. Extending into the member 30 and seating against its end wall,

there is an adjustable helical coil spring 33 which exerts sufiicient force to overcome the spring 32 and seat the valve member 24. The spring 33 is supported on an adjustable abutment member 34 carried by an adjustment screw 35 screw-threaded through a closure plug 36 which is screwthreaded into the open end of the inlet chamber 22. The screw 35 extends through packing gland 31 to prevent leakage therearound from the chamber 22. A cap nut 38 houses the external end of the screw 35 and is screw-threaded onto the plug 38. The plug 36 has a surrounding flange 39 which closes the open end of the inlet compartment 9 and which seats against the end face of the shell I, a sealing gasket 40 being interposed therebetween. 'The inlet compartment 9 communicates with the inlet chamber 22 through one or more ports or passageways 4! through the side wall of the body member l4.

The shell i has a circumferentially reduced end portion which provides, on the opposite side of the connections 2, 3 from the inlet connection 6, an annular shoulder 42. Seating on the shoulder 42 with the joint sealed by a gasket 43, there is a power element casing 44 having a neck portion which fits the reduced end portion of the shell I and forms therewith a pressure chamber 45. The

valve stem or rod 25 projects from the body member M into the chamber 45 and has a pad or plate 45, removablyscrew-threaded on its end. The plate 46 abuts a resilient metal diaphragm 4'! which closes the chamber 45 and is hermetically sealed to'the casing 44, the diaphragm responding to pressure changes inthe chamber 45 to movethe valve member 24. The chamber 45 is provided with an external equalizer connection 48 on the shell I, see Fig. 4, which communicates with the chamber 45 through a passageway 49 in the shell 4 and opening through the end wall I8. The connection 48 receives a conduit 50, hermetically sealed therein, as by brazing, and leading to the refrigerant suction or return line from the evaporatorsyas is well understood in the art. The diaphragm 4'1 forms the movable wall of a temperature responsive power element having a cover member 51 hermetically sealed to the diaphragm and to the casing 44 to provide an'expansiblecontractible chamber 52. One end of a feeler or bulb element tubing 53 is sealed in and through the cover member and has its other end closed and sealed. The tubing 53 and chamber 52 are charged with a temperature responsive liquid, such for example as Freon ormethyl chloride.

The power-element casing 44 has laterally extending apertured flanges; 54 (one only being shown) alined with laterally extending apertured flanges 55 projecting from the plug flange 39. The power element casing 44 and the body member. 54 are clamped and sealed to the shell I by bolts and nuts 5'5 which extend through and are pulled up against the pairs oifianges 54 and 55.

The operation is as followsrWhen it is desired to couple the valve to the refrigerant liquid and equalizer conduits, the nuts and bolts 56 are undone for removal of the casing 44 and diaphragm plate 46, afterwhich the body member |4can be withdrawn from the shell I. The conduits l, 5, i and 5e are now sealed to their shell connections, and the heat of brazing will not damage the power element or the valve mechanism. When the shell has cooled, the parts are reassembled and the valve is ready for operation. When the compressor is running and the evaporators are completely refrigerated, the liquid in the bulb element 53 responsive to suction line temperature adjacent the evaporator outlets, will have contracted or condensed so that the spring 33 will have closed the valve member 24. The evaporators will therefore warm up with a resultant increase of temperature of the bulb element 53 and expansion of chamber 52 which will open the valve member 24. This throttling of thevalve member 24 will continue until the compressor is stopped. When the compressor is again started, the valve member being open, the back-pressure in chamber 45 will act with the spring 33 to tend to close the valve member, thus regulating the refrigerant fiow through the valve until the power element bulb 53 again takes over the control.

It will be apparent that not only are the valve parts replaceable and interchangeable in the field, but also that manufacturing costs are reduced because a single size shell can be used for different valve port and member sizes and for diiierent size power elements.

Having thus described my invention, what is claimed and is desired to be secured by Letters Patent of the United States is:

1. In a thermostatic expansion valve, a tubula'r sheu'haviug'aconcentrically apertured end walla'nd an open end and an internal annular shoulder spaced from said end wall, a tubular body me e h in a los dnd. W d an wall having an external annular shoulder seating on said shoulder to divide said shell internally into an annular inlet compartment and an outlet compartment, said body member having an end wall having a projecting portionextending through said shell aperture and having a second annular shoulder seating on said shell endwall, said shell having an inlet passageway leading into said inlet compartment and having an outlet passageway leading from said outlet compartment, said body member having a valve seat therein separating said body member internally into an inlet chamber and an outlet chamber, said body member having a passagethrough its side wall connecting said inlet compartment to said: inlet chamber and having a Wa e -av on ectin sa d t e am e to said outlet compartment, a valve member cooperable with said seat, said body member having a surrounding shoulder seating against said shell to close said open end, a thermostatic power element having a movable operating member, and mounted on said shell, said surrounding shoulder and said power element'facing each other and f; eing spaced from each other by said shell, means operatively connecting said operating member to said valve member, and means clampingsaid body member surrounding shoulder and said power element to said shell.

2. In a thermostatic expansion valve, atubular shell having an open end: and. an internal annular shoulderspaced fromthe other end of said shell, a tubular body member having an end wall portion oiexternally reduced diameter and having intermediate said end portion and said open end an annular shoulder seating on said shoulder to divide said shell internally into an inlet compartment and an outlet compartment, said shell having an inlet passageway leading into said inlet compartment and having an outlet passageway leading from said outlet compartment, said body member having a valve seat therein separating saidbody member internally into an inlet chamber and an outlet chamber, said body member having a passageway connecting said inlet compartment to said inlet chamber and having a passageway extending-through the end wallp-ortion and cofnnectingsaidoutlet chamber to said outlet compartment, means sealing said end wall portion to said shell on the opposite side of said 'last named passageway from said body member shoulder, a'valve member cooperable with saidseat, said body member having asurrounding shoulder seating against said shell taining a temperature responsive operating meber operatively connecting said movable wall and said valve member, and means clamping said body member and said casing to said shell.

3. A thermostatic expansion valve comprising 1 a tubular shell having an end wall at one end and having its other end open, said end wall having a central opening therethrough providing an annular shoulder, said shell being internally enlarged to provide a second annular shoulder spaced from said first-named shoulder, a tubular body member seating on said first-named shoulder and closing said central opening and having an external annular shoulder seating on said second shoulder to divide said shell internally into an inlet compartment and an outlet compartment, said shell having an inlet passageway leading into said inlet compartment and having an outlet passageway leading from said outlet compartment, said body member having a valve seat therein separating said body member internally into an inlet chamber and an outlet chamber, said body member having a passageway connecting said inlet compartment to said inlet chamber and having a passageway connecting said outlet chamber to said outlet compartment, a valve member within said inlet chamber and cooperable with said seat, a plug fitting within said body member to close said inlet chamber and having a surrounding shoulder seating against said shell to close said open end, a thermostatic power element casing having an expansible chamber containing a temperature responsive operating medium and having a movable wall, said casing having a tubular extension seating on the end of said shell opposite said open end, said shell having an equalizer passageway opening into the interior of said extension, said body member having a guideway concentric with said seat and connecting the interior of said extension to said outlet chamber, a thrust member reciprocal in said guideway and operatively connecting said movable wall and said valve member, clamping flanges extending laterally from said casing and from said plug, and bolts cooperable with said clamping flanges and extending longitudinally of said shell to clamp said body member, said plug shoulder and said casing to said shell.

4. A thermostatic expansion valve comprising a tubular shell having an end wall at one end and having its other end open, said end wall having a central opening therethrough providing an annular shoulder, said shell being internally enlarged to provide a second annular shoulder spaced from said first-named shoulder, a tubular body member seating on said first-named shoulder and closing said central opening and having an external annular shoulder seating on said second shoulder to divide said shell internally into an inlet compartment and an outlet compartment, said shell having an inlet passageway leading into said inlet compartment and having an outlet passageway leading from said outlet compartment, said body member having a valve seat therein separating said body member internally into an inlet chamber and an outlet chamber, said body member having a passageway connecting said inlet compartment to said inlet chamber and having a passageway connecting said outlet chamber to said outlet compartment, a valve member within said inlet chamber and cooperable with said seat, said body member having a surrounding shoulder seating 3 against said shell to close said open end, a thermostatic power element casing having an expansible chamber containing a temperature responsiveoperating medium and havinga movable wall, said casing having a tubular extension seating on the end ofsaid shell opposite said open end, said body member having a guideway concentric with said seat and connecting the interior of said extension to said outlet chamber, a thrust member reciprocal in said guideway and operatively connecting said movable wall and said valve member, and clamping means for securing said casing and said body member to said shell.

5. A thermostatic expansion valve comprising a tubular shell having an open end and an internally enlarged portion providing an annular shoulder, a tubular body member having an external annular shoulder seating on said firstnamed shoulder to divide said shell internally into an inlet compartment and an outlet compartment, said shell having an inlet passageway leading into said inlet compartment and having an outlet passageway leading from said outlet compartment, said body member having a valve seat therein separating said body member internally into an inlet chamber and an outlet chamber, said body member having a passageway connecting said inlet compartment to said inlet chamber and having a passageway connecting said outlet chamber to said outlet compartment, a valve member within said inlet chamber and cooperable with said seat, a plug fitting within said body member to close said inlet chamber and having a surrounding shoulder seating against said shell to close said open end, a thermostatic power element casing having an expansible chamber containing a temperature responsive operating medium and having a movable wall, said casing having a tubular extension seating on the end of said shell opposite said open end, said body member having a guideway concentric with said seat and connecting the interior of said extension to said outlet chamber, a thrust member reciprocal in said guideway and operatively connecting said movable wall and said valve member, clamping flanges extending laterally from said casing and from said plug, and bolts cooperable with said clamping flanges and extending longitudinally of said shell to clamp said body member, said plug shoulder and said casing to said shell.

6. In a thermostatic expansion valve, a tubular shell having an open end and an internal annular shoulder, a tubular body member having a closed end wall, said end wall having an annular shoulder seating on said shoulder to divide said shell internally into an inlet compartment and an outlet compartment, said shell having an inlet passageway leading into said inlet compartment and having an outlet passageway leading from said outlet compartment, said body member having a valve seat forming a valve port, said body member having a passageway leading from said port to said outlet compartment, a valve member -cooperable with said seat, said body member having a surrounding shoulder seating against said shell to close said open end, a thermostatic power element having a movable operating member and mounted on said shell and spaced from said body member end wall, means operatively connecting said operating member to said valve member, an equalizer passageway opening through said'body zse'sg see member end wall into the space between said body member and wall and said power element, and means clamping said body member and said power element to said shell.

FRANIQYN Y. CARTER.

REFERENCES CITED The following references are of record in the file of this patent:

STATES PATENTS Number Name Dat Cash Apr. 18, 1916 Hoffman Nov. 25, 1930 Dube et a1 Oct. 19, 1937 Newton June 14, 1938 Anderson et a1 Dec. 5. 1939 Dillman et a1 Sept. 12, 1944 

